If the smoke stops after running for a while then it is just condensation in the exaust system and its normal. If it never stops and smells sweet, then it is antifreeze and you need a new headgasket. The most likely cause of running rough would be that gas breaks down over time and turns into varnish. I agree with the techron suggestion. Fill up the tank, add techron and keep driving. If you have to leave the car sitting for months without driving it next time add some Staybil (spelling?) to the tank, and keep the tank to keep the gas from breaking down and at the same time fillup the tank to keep condensation for forming in the gas tank. Hope that helps and good luck.

Hi Dylan,

Cars really like to be driven and they have a way of getting back
at us when we let them sit idle!! ;)

Just kidding, but I agree with the previous posts, the color of the
smoke is the important information that is needed to determine the
root cause of the problem.

I would get some Techron injector cleaner at Autozone, or equiv, and
run that through your fuel system. It has worked wonders on my '86
with over 220K miles several times. Also change your oil,
and then drive it at highway speeds to clean the fuel system and
combustion chambers out.

A good tune up of air filter (Mann), plugs, plug wires, distributor cap,
and rotor would also be a good thing. But I would give the Techron a
chance to work (at least one to two tanks with Techron in each one) before
doing the tuneup. You may also need to do a new fuel filter. All of this
is quite inexpensive if you get the parts from our brickboard advertisers
and put them on yourself.

Good luck!

TomD
'86 240
'93 240

What color was the smoke? does it idle below 1000 rpm's? Or stall when idleing? it could be bad plugs,bad fuel pressure regulator,or fuel pump relay,or jetronic computer. I have a jetronic computer if that's the problem......they are expinsive at the dealership...if you need one I have one for $50.00 plus shipping....volvo240guy@aol.com

An important thing to know here is the color of the smoke. Is it blue, black, or white? If it's blue, you're burning oil. If it's black, too much gasoline is getting into the combustion chamber. If it's white, water is getting into the combustion chamber. Each of these has its own set of possibilites as to the root cause of your problem.

Tim
--
Tim Smith '85 745GLE M46 w/86k

It might be possible that you have water in the gas tank, but I don't think that would explain the smoking. A friend of mine let his car sit for a few months over the winter and when he came back it ran very rough. He had water in the fuel system but it didn't smoke that I am aware of. It might mean a bad head gasket, but that is only a guess.

-Mark